In the processing of roll film the film is not cut into individual views or frames prior to processing but rather, the entire roll is processed at one time. A spiral roll mounting device has been provided for holding the film during the processing thereof and the spiral effect provides a means for holding the turns of the film remotely from one another to allow the proper flow of developer against all of the film surfaces. This spiral unit allows a compact configuration for the developing of film as compared to a system where the film is hung or otherwise rolled out into a continuous line arrangement.
These sprial film holders provide a means for receiving and holding one end of the film strip at the central portion of the spiral reel but to this time there has been no convenient means for locking the other end of the film onto the reel. With no outer locking arrangement, vigorous flow of the developing fluid has been known to dislodge the film from the reel. This situation is particularly aggravated due to the fact that the holder into which the filled reels are placed is agitated during the development process.
The only such holding device of which the applicant is aware provides a unit which overlies the entire free end of the film and when locked into the reel often brings the adjacent rolls of film into contact with each other thus defeating the purpose of the spiral placement of the film.
With applicant's retention or clip device, the free end of a roll of film is engaged on the side edges thereof and these side edges are clamped to the elements forming the sprial of the reel and the clip itself. In this manner, it is possible to place the clip at any radial position of the reel and lock the free end of the film at any point on the reel. This is particularly important when developing relatively short film strips as the strip, when wound upon the spiral reel, will not extend to the outer periphery thereof.
It is therefore an object of applicants invention to provide a film retention device for holding film strip material onto spiral reel development units which retention device will retain the peripheral edges of the film against the spiral wound elements of the reel and prevent the film from accidentally being removed from or falling from the reel during the development process.
It is a further object of applicants invention to provide a film retention device for use with spiral development reels wherein the device is deformable and held into the spiral reel through the spring tension thereof.
It is still a further object of applicants invention to provide a film retention device for use with spiral reel film holders of various sizes to therefore accomodate films of various sizes, the reel holder of course being sized in accordance with the film.
It is yet a further object of applicants invention to provide a film retention device which is easily placed into a spiral reel film holding unit and easily removable therefrom and will clamp the peripheral edges of the film during its placement into the reel.